Fleet Maintenance Cost per Mile: How to Calculate It for a Small Fleet

Most small fleets know roughly what they spend on maintenance each year. Fewer can say which vehicle spent it, or whether it was a lot for the miles driven. Cost per mile answers both. It turns a pile of invoices into one number per vehicle that you can compare across the fleet and from one year to the next.

The pages that rank for this topic are mostly written for long-haul carriers running hundreds of Class 8 tractors with telematics. This guide is for the other end: 3 to 30 vans, pickups, box trucks, and maybe a machine or two on an hour meter, where the mileage comes from someone reading an odometer and the invoices live in a folder.

The formula, and what goes into it

The math is one line:

Maintenance cost per mile = maintenance and repair spend ÷ miles driven (same vehicles, same period)

Miles driven is the odometer at the end of the period minus the odometer at the start. Not the current odometer reading: a 140,000-mile truck that drove 15,000 miles this year divides by 15,000.

Every argument about cost per mile is about the top half of that fraction. There is no single industry standard, so pick a rule, write it down, and keep it. This is a sensible default for a small fleet:

Tires are the one judgment call. They are real wear costs, but a set lands in a single month and can double a vehicle’s figure for that quarter. Tracking them as their own line makes the maintenance trend easier to read. If you do include them, say so, because the two benchmarks below disagree on this point.

In-house labor is the other trap. If your own mechanic or a crew member does oil changes on Friday afternoons, that time costs money even though no invoice shows it. Add a shop rate per hour of logged labor, or at least note which vehicles were serviced in-house, so a DIY van doesn’t look cheaper than it is.

Get the miles right first

A wrong mileage figure wrecks the number more quietly than a missing invoice. Three rules:

1. Read odometers on a fixed day. First Monday of the month is enough for cost per mile. Weekly is better if the same readings drive your service reminders.
2. Record the odometer on every invoice. Most shops print it. If yours doesn’t, write it on the invoice before it gets filed. That reading lets you rebuild mileage for any period later.
3. Use the same 12 months for cost and miles. Costs from January to December divided by miles from March to March produces a number that means nothing.

Use a rolling 12 months rather than a calendar quarter. Maintenance is lumpy: an annual inspection, a brake job, and a battery can all hit one vehicle in the same month. Twelve months smooths that out, and a monthly recalculation still shows a trend.

Worked example: a 6-vehicle mixed fleet

A landscaping and irrigation company runs two cargo vans, three pickups, and a box truck. Here is the last 12 months from its service records, tires excluded:

The fleet figure is total cost divided by total miles ($19,850 ÷ 114,500), not the average of the six percentages. Averaging the per-vehicle figures would give 18 cents and let the low-mileage pickup count as much as the busiest van.

The fleet number looks unremarkable. The per-vehicle column tells three stories:

• P2 is a repair, not a trend. Its $5,320 breaks down into $1,050 of scheduled services, a $3,100 transmission repair, and $1,170 of front-end parts. Only 20% of its spending was planned. Without the transmission it ran 14.6 cents a mile, close to V2. Watch the next 12 months before deciding anything, but log the repair date so you know when it drops out of the rolling window.
• B1 is expensive for its class, and that may be fine. A box truck has more to service than a van, plus a body and liftgate. Compare it with itself last year, not with the pickups. If you add a second box truck, compare the two.
• P3 looks pricey only because it barely moves. Its $1,470 is mostly calendar-driven: two oil changes on the 6-month limit, an inspection, a battery. Spread over 9,800 miles, that looks worse than it is. For low-mileage units, also look at cost per month (here about $123) before reading too much into the per-mile figure.

Tires that year were $2,900 across V2, P2, and B1. Add them in and the fleet figure rises to 19.9 cents ($22,750 ÷ 114,500). Neither number is wrong; mixing the two from one year to the next is.

Benchmarks: what is normal for vans, pickups, and trucks

Most of the numbers floating around come from vendors with different definitions, so use published studies and check what each one includes before comparing:

AAA’s 2025 fact sheet is the best public figure for light-duty vehicles, with two caveats. It is built on new vehicles driven about 15,000 miles a year for five years, and it includes an extended warranty. A fleet of six-year-old work vans will run higher, and the AAA brochure’s per-category table shows how narrow the spread is between new vehicle types (about 10 to 12 cents).

For heavy trucks, the American Transportation Research Institute reported repair and maintenance up 8.6% in 2025, with average truck age and annual mileage rising as carriers cut capacity. FreightWaves’ summary of the report gives the per-mile figures: 21.5 cents for repair and maintenance and 5 cents for tires. Those are long-haul tractors running high annual miles; a box truck on city routes will usually sit above that.

The age figures from Fleetio’s data in FleetOwner mix every vehicle type together, so don’t hold one pickup to them. The shape is the useful part: cost per mile more than doubled after year five in that dataset. In the worked example, the three newest vehicles ran 7 to 15 cents and the three oldest 16 to 35 cents.

The most useful benchmark is your own fleet: the same vehicle last year, and the same class of vehicle across your units.

What drives cost per mile up

• Age and odometer. Warranty runs out, and wear items and drivetrain repairs arrive. This is the biggest driver in every dataset.
• Duty cycle. Stop-and-go delivery, idling, towing, and job-site dirt roads wear brakes, suspension, and filters faster than highway miles. Many owner’s manuals call this severe service and shorten the intervals for it.
• Low annual mileage. Calendar-based services cost the same whether a truck drives 8,000 or 25,000 miles, so lightly used units look expensive per mile.
• Unplanned repairs. A tow plus a shop’s emergency rate costs more than the same repair booked ahead. Track what share of each vehicle’s spending was scheduled; a falling share is an early warning.
• Skipped preventive maintenance. A missed coolant or transmission service is cheap this year and expensive later, which is why a preventive maintenance program usually lowers cost per mile over time even though it adds scheduled visits.

Using the number: repair, reschedule, or replace

Cost per mile is a signal, not a verdict. A simple quarterly routine:

1. Rank vehicles within each class. Vans against vans, pickups against pickups. Flag anything well above its siblings.
2. Open the flagged vehicle’s history. One big repair (like P2’s transmission) is different from a steady climb of brakes, sensors, and suspension parts.
3. Check the planned share. If most spending was unscheduled, look at whether services are happening on time before blaming the vehicle.
4. Compare next year’s likely repairs with the vehicle’s value. When the expected repair bill approaches what the truck is worth, start pricing a replacement. Good records also help at sale time; see how maintenance records affect resale value.

Equipment on hour meters gets the same treatment with hours instead of miles. A skid steer that logged 410 hours and $2,460 in maintenance over 12 months costs $6.00 an hour. Don’t mix per-hour and per-mile units in one fleet figure; report them side by side.

How to keep records that make this easy

Every cost record needs five fields, or it can’t be used later:

1. Unit number or VIN, so the cost lands on the right vehicle.
2. Date of service.
3. Odometer or hour-meter reading at the time of service.
4. Category: scheduled, unscheduled, tires, or collision. This is what lets you include or exclude consistently.
5. Total cost, with the invoice attached or filed by unit.

For a few vehicles, the free fleet maintenance spreadsheet has these columns ready; add a monthly odometer tab and a SUMIFS by unit and date range. Keep fill-ups in a separate fuel and mileage tracker so fuel never leaks into the maintenance figure. Once several people are logging work and the monthly recalculation starts slipping, read when a spreadsheet stops being enough.

Common mistakes

• Dividing by the total odometer. Lifetime miles make an old truck look cheap. Use miles driven in the period.
• Mismatched periods. Twelve months of invoices over nine months of mileage inflates the figure by a third.
• Averaging the averages. Divide total cost by total miles for the fleet figure.
• Changing the rule. Including tires one year and not the next creates a trend that isn’t there.
• Comparing a van to a tractor benchmark. Use the benchmark for the vehicle class, or better, your own history.
• Ignoring missing invoices. A vehicle with no recorded spending for six months is either very healthy or being serviced off the books. Find out which.